Prostitute to cat burglar is no way a logical shift.
And then there's the skillset itself. Selina's, so impressive and masterful that it can only have been a lifelong effort, is that of the thief: stealth, lock- and pocket-picking, acrobatics, specialized tool use (crampons, glass-cutters, d-cel), and, at this point in her canon, big cat taming - things that one learns for the express purpose of theft, develops through a repeated reliance on theft, or turns to theft as a result of possessing. None of which makes any sense from prostitute!